In agriculture, it is common to make use of air distributions systems for delivery of seed or fertilizer to furrows formed in the ground by respective furrow openers of a suitable implement. As the force of air exiting distribution tubes of the air distribution system can inadvertently cause the material being distributed to be blown out of the furrow, the use of the various types of material decelerating devices are known. Two examples of material decelerating devices are described in U.S. Pat. No. 7,509,915 by Memory and U.S. Pat. No. 4,493,273 by Gauchet et al. In each instance, a cyclonic separator is used to separate the material being conveyed from the conveying air stream. Using the designs of the prior art however, lighter materials can be caught in the conical air flow and inadvertently exhausted out of the upper air vent instead of the product delivery opening at the bottom end. In other instances, the material being conveyed may be trapped within the cyclonic flow of air within the separator.
US Patent Application Publication 2002/0144637 by Wendling et al. discloses a further example of a cyclonic separator in an agricultural air distribution system in which the interior of the cyclonic chamber includes a helical groove formed therein. The groove is very shallow relative to the overall diameter of the chamber such that most of the air flow is not affected by the groove and material may still spin uncontrollably within the cyclonic air flow instead of being assisted by the groove to the material outlet at the bottom. Furthermore, the material and air inlet enters the cyclonic chamber within a plane which is near perpendicular to the axial direction of the chamber such that the air flow may be substantially circular and lighter materials may eventually be exhausted through the upper vent opening instead of the lower material outlet as in the prior art examples noted above.